Honda EXT12D Maintenance Manual page 48

Storage
1. Clean each generator component.
2. Check each part according to the maintenance schedule and repair/
service the faulty parts.
3. Replace the engine oil with fresh oil before operating the generator
after storage.
Refer to page
4. Fill the fuel tank with fresh diesel fuel.
5. Disconnect the battery ground cable from the terminal and tape it.
While storing the battery, fully charge the battery once a month.
6. Cover the generator and place it in a well ventilated and dry area. If
the generator is still hot, wait until it cools down cover.
Remove the radiator cap and check the coolant level before operating
the generator after storage. If the coolant level is low see your
authorized Honda dealer.
48
40 for engine oil replacement.